Register decimal markers



March 1963 w. s. GUBELMANN REGISTER DECIMAL MARKERS Original Filed May27, 1957 "I I: p;

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INVENTOR WILLIAM sauemMNN March 1953 w. s. GUBELMANN REGISTER DECIMALMARKERS Original Filed May 27, 1957 3 Sheets-Sheet 2 INVENTOR.

BY WlLLlAM sauawhmw March 26, 1963 w. s. GUBELMANN REGISTER DECIMALMARKERS 3 Sheets-Sheet 3 Original Filed May 27, 1957 R m v N E w.

WILLIAM S. GUBELMANN ATTORNEY United States Patent 3,082,944 REGISTERDEQIMAL MARKERS William S. Gnheirnann, Convent, Null, assignor to Realtyand lndustriai Corporation, Convent, Ni, 2 corporation of New ZierseyGriginal application May 27, 1957, Ser. No. 661,971, now Fat-eat No.2,959,131, dated .ian. 24, 1961. Divided and this appiication Aug. '7,1955}, Ser. No. 753,832 11 Claims. (Ci. 235-611) This invention relatesto calculating machines, computing machines or the like.

An object of this invention is to provide an improvement in a computingmachine of the type that has several registers in an ordinally shiftablecarriage and also has several banks of digital keys for entering certainfactors into a computation, and including elements for selectivelyindicating the location of a reference point such as a decimal, or otherdelineations, between adjacent orders of such registers and banks ofkeys.

Another object of the invention is to provide means for minimizing thesubjective influence of the operator over sequence when following theprescribed mode of decimalizing operation steps.

Still another object of this invention is to provide an improved,inexpensively manufacturable pointer and rail therefor, which pointer iseasily adjustable to indicate the location of a reference point ordecimal, of a registration in a register.

It is a further object of the invention to provide a decimal locationpointer and a rail therefor, preferably a channel strip with numerals orlike symbols placed on the visible internal face of its base tofacilitate adjustment of the pointer, the elevated sides of the channelserving to prevent marring of the internal face as during shifting ofthe pointer.

Still another object of the invention is to provide a shiftable markerfor setting the marker to locate the decimal of a quotient in a registerof a computing machine, which machine in each of successive cycles ofoperations, selects the one of predetermined quotient digits that hasresulting relation with the highest order of the dividend and of the twohighest orders of the dividend remainder divided by the highest orderdigit 1 to 9 of the divisor.

The foregoing and other objects and advantages of the invention will bemore readily understood upon reference to the following description. Itwill be apparent, however, that those skilled in the art will be enabledto apply the teachings of this disclosure to various modifications asintended to be covered by the scope of the appended claims. Thedescription is directed to a preferred exemplary embodiment of theinvention illustrated in the accompanying drawings forming a parthereof, in which:

FIGURE 1 is a top face view of a calculating machine according to theinvention, the carriage being shown in fragment in its leftmostposition.

FIGURE 2 is a fragmentary top face view similar to that of FIGURE 1, butshowing'the carriage shifted all the way to the right.

FIGURE 3 is a fragmentary perspective detail view showing one form ofmovable indexing marker element engaged with its supporting channelrail, apart from the machine.

FIGURE 4 is a fragmentary perspective detail view of another form ofmovable indexing marker element carried on its supporting guide channel,apart from the machine.

FIGURE 5 is a View showing in cross-section the indexing marker elementof FIG. 4 and its guide channel.

FIGURE 6 is a fragmentary perspective detail view of a still anotherform of movable indexing marker assoice ciated with its channelsupport,apart from the machine.

FIGURE 7 is a fragmentary sectional elevat-ional view takensubstantially on plane 7-7 of FIGURE 1, showing principally a keyboarddecimal marker and the decimal pointers and rails for the severalregisters, with dials, and omitting other parts for clarity.

This application is a division-in-part and continuationin-part of mycopending patent application, Serial No. 194,273, filed November 6,1950, for Partial Product Calculating Machine (Patent No. 2,969,177) andis a division of my copending patent application, Serial No. 661,971,filed May 27, 1957, for Keyboard Decimal Markers and the Like (PatentNo. 2,969,181).

GENERAL DESCRIPTION The machine in which the present invention isembodied is disclosed in detail in the aforementioned parentapplication, Serial No. 194,273, and the division andcontinuation-in-part application thereof, Serial No. 661,971, to whichreference may be had for a complete disclosure not otherwise repeatedherein. A brief summary of the machine and its operations, however, ispresented herewith in order to facilitate understanding of the use ofcertain decimal markers and the methods devised for setting them.

The machine shown in FIG. 1 embodies partial product and predeterminedquotient devices, a shiftable carriage 1 which carries counter andaccumulator registers 2 and 3, several banks of keys 4 for setting upfactors in various arithmetical calculations, and a bank of multiplierkeys 5. This machine, commonly known as a fourrules calculator, performsthe arithmetical calculations of addition, subtraction, multiplication,and division automatically.

Multiplication is direct, as distinguished from repeated addition inthat the machine multiplies in a manner closely analogous to the methodused in mental computations. Representations of products for digits 0 to9 times 1 to 9 are provided for selection in accordance with theseparate digits of the multiplicand and each multiplier digit. Thepartial products thus obtained are then integrated into the finalproduct.

Addition and subtraction calculations are penformed by automaticallytreating the factors thereof as multiplicands, and multiplying thefactors by 1. The product thus obtained of a swbtnahend is registeredsubtractively by the dials of the respective register. Selective meansis also provided for effecting subtractive registration of otherproducts.

Heretofore division computations have been performed by repeatedsubtraction or logarithmic processes. In this machine division isaccomplished directly by structural elements in 'a manner analogous tothe method corresponding to the well known mental procedure in longdivision. The mechanism used for a calculation in division includesmeans for deriving trial quotient digits and also makes use of themultiplying mechanism. This means that when a dividend has been set upin register 3 and a divisor has been set up in keys 4 of the keyboard,the machine upon actuation by depression of either division key 6 or 7automatically selects a trial quotient and causes the multiplyingmechanism to obtain the prodnct of the divisor times the trial digit.The product is then subtractively registered in dividend register 3.

Selection of a trial quotient value is made from representations ofquotient values provided for dividend numbers ranging from O to 99divided by divisor digits 1 to 9, both inclusive. The trial quotientfirst obtained may be an over-estimation. In that case, the mechanismautomatically reduces the trial quotient by 1 and makes one or morefurther attempts to obtain the true quotient. When the true quotient, asingle digit, is so obtained, it is registered in register 2. Failuresto obtain the true quotient are evidenced by an over-draft from thedividend, which is automatically cancelled out by adding back intoregister 3 the amount subtracted therefrom, that is, the product of thedivisor times the trial quotient which proved to be too large. In themajority of instances the trial quotient proves to be the true quotient.The need for repeating more than once the attempt to obtain the truequotient integeris relatively infrequent. Under-estimation, i.e.,selection of a too small quotient integer, is not possible, due to thepositive stop arrangements, as explained in the afore mentioned parentapplication.

Results and factors of the various computations are indicated inordinally disposed dials of registers 2, 3 and 8 as follows: Register 2,carried by the carriage, can indicate the multiplier, quotient, or thenumber of items in addition or subtraction as the case may be and,alternatively, the complement of any of the foregoing. Register 3, alsocarried by the carriage, similarly can indicate the product, dividend,sum, difference, or such complements thereof as are desired. Stationaryregister 8 shows for easy reading a currently set up factor on the keys4. Each register includes dials as at 9, 10 and 11, the numerals ofwhich are visible through suitable apertures on the respectiveoverlying'cover plates.

Each multiplier key 5 for values l-9 exercises a controlover thecomputing mechanism for setting up significant partial products andsimultaneously serves as an initiatory control for effecting operationof the computati'ng mechanism. The cycle of operations so institutedalso includes the function of automatically initiating operations for anordinal shift of the carriage. Depression of the value key serves toinitiate an ordinal shift of the carriage without first having to excitethe computing mechanism.

Selectively operable keys 12, 13 and 14, near the right hand edge ofFIG. 1, are provided for controlling the direction of shift of thecarriage as for multiplication. With key 12 in depressed position, theautomatic ordinal shift of the carriage will be leftward, but with key14 in depressed position instead, the ordinal shift will be right ward,as indicated by the arrows on these keys. In each instance, the carriagewill shift in the opposite direction for return to a preselected startposition with the use of carriage return key 15. With the nonshift key13 in depressed position, the automatically operated shift initiatingmeans is disabled.

The tabulating mechanism is so constructed as to stop the carriage at anordinal position by directly causing the carriage traversing mechanismto stop its operation. The tabulating mechanism is brought intooperation each time the carriage shifts to either end position. Suchoperation of the mechanism will also occur at an intermediate ordinalposition as with the use of key 15 provided that preselection of thatposition is made by depression of an appropriate one of tabulator keys16, which are self-lockable and are releasable upon depression of a tabclear key 17 at either end.

Add key 18 and subtract key 19 are in effect 1 value multiplier keys,but the cycles of operations instituted thereby do not include theautomatic initiation of a shift operation. Two divide keys 6 and 7 areprovided, either of which serves to inititate a division computationcycle of operations, provided the machine is properly set up for such acomputation.

The machine is prepared for a division computation as follows: Thecarriage is shifted to its rightmost position, as illustrated in FIG. 2,preferably by the depression of extreme shift key 20, FIG. 1. Thedividend is then set up in the multiplioand selecting mechanism by keys4, preferably with the highest order of the dividend in the leftmostbank of keys 4. With the use of add key 18, the dividend is registered,that is to say, entered, in register 3 with the highest order appearingin the 19th order dial 9, FIG. 2, the lower of the two highest orderinboard dials. (An inboard dial is one which is in operative relationwith the entry and carry mechanisms of the main body of the machine.) Atthis rightmost position of the carriag the 19th dial is then inalignment with the leftmost keybank to receive a registration therefrom.Non entry key 21 (FIG. 1) is depressed simultaneously with the add key18 whereby the item 1 is prevented from appearing in register 2. Thedivisor is then set up in the muitiplicand selecting mechanism by keys 4with the highest order real digit, that is, a digit other than 0, in theleftmost bank. In addition to making a selection of relative partialproducts, the depressed key in the leftmost bank also effects selectionof quotient representations in the dividing mechanism in accordance withthe value of that key.

Depression of a divide key is prevented by a system of locks which arerendered ineffective only when both the carriage is in its rightmostposition and a real digit key 4 is depressed in the leftmost bank.Operation of either key 6 or 7 excites a mechanism which conditions themachine (Without upsetting current operational setups that may beincongruous with requirements for division) for subtractive entry ofproducts, and for sequential operations of the division, multiplying andtraversing mechanism, the latter to shift the carriage leftward. Theconditioning mechanism also initiates operation of the dividingmechanism for the division process. With the use of key 7, theconditioning mechanism also renders the tabulating mechanism effectiveto cause termination of the division process upon registration of apredetermined number of quotient digits. First, however, the tabulatingmechanism must be set by depression of that tabulator key 16 whichcorresponds with the number of digits desired. With the use of key 6,whether or not a tabulator key selection is made, or with the used ofkey 7 when a selection is not made, the tabulating mechanism will causetermination of the process only when the ordinal capacity of the machineis reached.

In algebraic division processes, the problem is solved" whenever thedividend is eliminated, that is, reduced to 0. Sensing means, one foreach dial 9, are all movable together and movement is obstructed when adial 9 is displaced from 0 position, indicating a remainder.Accordingly, turning of all the dividend dials 9 to 0 position enablesthe sensing means to move, whereupon the sensing means effectstermination of the division process automatically, there being noremainder and no reason for continuing the operations. Both theeliminated dividend sensing means and the tabulatin g mechanism operatea mechanism which terminates the division process by preventing thesequential re-initiation of the dividing mechanism after the final truequotient digit is registered in register 2.

The preferred method of carrying out a cycle of operations in a divisionprocess in this machine after the problem is setup is as follows: Thevalue of the dividend digits in the two highest inboard orders of dials9 of register 3, the 20th and 19th dials (FIG. 2) in the initial cycle,is sensed. (The value in the 20th dial being 0 and in the 19th the valuebeing that of the highest order numeral of the dividend.) In accordancewith the sensed dividend value, the significant quotient valuerepresentation of the divisor selected representations is set up insidethe machine. Then the set up representation is sensed and concurrentlythe multiplier controls in the computing mechanism are adjusted for thattrial quotient value. Next, a cycle of operations of the computingmechanism is automatically instituted, whereby the product of thedivisor factor (the multiplicand) by the trial quotient digit (themultiplier) is subtracted from the dividend in register 3 and the trialquotient is registered in the first inboard order dial lid, of register2, FIG. 1, the 10th or leftmost dial in the initial phase of thedivision process, at which time that dial is standing in alignment withthe numeral 0 on the decimal marker channel 22. When subtraction of theproduct does not result in an overdraft, as would be indicated onregister 3, a cycle of operations is instituted automatically forshifting the carriage leftward one step. In the final phase of the shiftcycle, operation of the dividing mechanism is instituted again, thistime automatically, except, however, when the carriage has been shiftedto its leftmost position, or to a preselected ordinal position, orwhenever the dividend has been eliminated, showing that a solution hasbeen reached. In the event an over-draft occurs, the overdrafting amountand the too large quotient digit entries are withdrawn from therespective registers 3 and 2. At the same time the dividing mechanismautomatically reduces the value of the too large quotient digit by l andadjusts the multiplier controls accordingly. The multiplying mechanismis then automatically caused to obtain the product of the divisiorfactor times the reduced trial quotient value and to reduce the dividendby that product. If the value of a selected trial quotient or of areduced trial quotient is 0, a shift cycle of operations for shiftingthe carriage one step leftward is automatically in stituted instead ofthe normal subsequent multiplying process.

Selectively settable decimal marker members 23 (FIG. 1), 24 and 25 areprovided for indicating decimals of factors set up by keys 4 and ofregistrations in registers 2 and 3 respectively.

DECIMAL MARKERS Markers 23 in one form are elongated prismatic bars, thedegree of elongation being made suflicient to suit the constructionalneeds and arrangements. Each bar is formed with more than two facesabout its longitudinal axis, this being the axis about which it ismounted for turning. A bar 23 is disposed intermediate. each adjacentbanks of keys 4, there being nine such bar shown by way of example.These bar markers are rotatably mounted at their forward or proximalends on upturned flange 26 (FIG. 7) of keyboard frame plate 27, and attheir rearward ends on keyboard register cover plate 28 which issupported by plate 27. According to one preferred form, markers 23 aretriangular in cross section, each normally having only one of its threefaces visible to the operator, the face then being in a plane parallelwith the plane of plate 27 which serves as the background for thekeyboard, as viewed in FIG. 1.

Slightly rearwardly of flange 26 (FIG. 7) a turning means 29 is securedto each bar 23 for movement therewith. Each turning means protrudesupwardly through suitably located frame openings 30 on the over-hangingportion 31 of cover plate 32, which is in front of keys 4. This locationis not only convenient for the operator but also avoids interferencewith or accidental depression of keys 4 while manipulating, a turningmeans for rotating a selected bar marker so as to bring any one of itsthree faces into direct line of vision of the operator.

In one preferred form, the surface of one face of each bar 23 matchesthe visible surface of the background plate 27 so as to blend or mergetherewith and thus be indistinguishable therefrom when brought intoviewing position, thereby avoiding the representation of a decimal or ofany other delineation. Each of the other two faces of the bars may besurfaced mutually similarly but differently from that of the backgroundsurface, or the two faces may be surfaced differently from each otherand from the background plate or wall. Then when one of the differentlysurfaced faces of a bar is turned into viewing position it contrastswith the background, distinctly delineating the adjacent banks of keys,whereby to represent a decimal, a point, line or location ofdemarcation.

Referring to FIG. 1, selectively settable decimal markers or indexingmembers 24, 25, and 41 are mounted respectively on channel rails 42, 43,:22 and 44. Channel rails 22 and 44 are secured respectively to coverplates 32 and 28 of the machine and rails 42 and 43 are secured to cover45 of carriage 1 for movement therewith. Each member or rail is formedof flanges 46, as may be est seen in FIG. 6, projecting divergentlyoutwardly from web 47, and the decimal markers may be suitably shapedwith depending spring fingers 48 to yieldably grip the inclined flanges46, as shown, for sliding therealong. The markers are spaced from thechannel web and are formed with indexing fingers 49 (FIG. 3) of a lengthsufficient to extend as between adjacent orders of the related registerfor decimalization of a registration therein, and these fingers may bemarked with a suitable colored spot. A suitable knob 50 is secured toeach marker for sliding .or setting the marker from one decimalizingposition to another. The ends of each of the rails are bent upwardly toform stops 51 (FIGS. 6, 7) for blocking endwise disengagement of therespective marker from the channel rail.

Referring to FIG. 1, the visible face of web 47 of each of the rails 22,42 and 43 is marked as with numerals, preferably reading from right toleft, to coincide with the register orders so as to facilitatepositioning of the markers for decimalizing. These numerals may bemarked on the visible face of web 47 in any well known manner, as bypainting. The flanges 46 of the channels serve to prevent obliterationof such markings. It will be noted that rail 44 is preferably notprovided with serialized indicia or markings, as are the other rails,and that decimal marker 41 thereon has two oppositely oriented indexingfingers 49a and 49b instead of one as do the other markers. The proximalfinger 49a extends towards the keyboard so as to align selectively withkey bank decimal markers 23, and the opposite finger 49b extends towardsregister 3 for indicating a decimal between adjacent orders of the dialstherein.

Some of the rails are shown with more than one marker to facilitate useof the one closest to the location at which the operation is beingcarried on. A series of lines 52 are marked on machine cover 28extending from dials 11 of register 8 toward the registers on thecarriage. Coinciding lines '52 are continued on carriage cover 45 todials '9 of register 3, dials 10 of register 2 toward the numeralsmarked on channel 22. These lines are provided for facilitatingdecimalizing. Methods for decimalizing operations for division andmultiplication computations are explained hereinafter.

FIGURE 3 shows another form of slidable marker in which the top webextending across the channel rail has a depending skirt 48a with springpressure fingers 53 extending therefrom to resiliency grip theunderlying side flange of the rail. It is only necessary to have thepressure fingers 53 on one of the skirts 48a, inasmuch as that one pairof fingers acting against one outer face of the channel rail will drawthe other two skirts 48a against the opposite outer face.

FIGURES 4 and 5 illustrate a further form of slidable marker in whichthere is a marker body with tapered lower portion '54 conforming to andextending inbetween the inner angle space of the channel, leavingclearance therebelow to avoid touching any numerals, or other indiciacarried on the visible web face 47a. A spring clip 56 may be snappedinto a shallow transverse groove 55 on the marker body, so that itsspring fingers extend over and grip the outside flange surfaces of therail, allowing controlled slidable positioning therealong. For increasedwedging effect the two shoulders 57 riding on the upper edge of the railflanges may, if desired, be omitted. The spring clip 56 may serve as aconvenient lining pointer having a function somewhat similar to thepointer 49 of FIG. 3, and may be variously or brightly colored orvsurfaced to enhance its pointing effect, and may project partly abovethe marker body so that depression thereof spreads its fingers,releasing their gripping action for easy sliding.

DECIMALS IN DIVISION The rules for the procedural sequence or steps forsetting indexing means 24 (FIG. 1) for decimalizing quotients registeredin register 2 will now be given. First,

however, it will be recalled that the machine can be cycled for theperformance of a division calculation only when the carriage 1 is in itsrightmost position, as shown in FIG. 2, at which time the 19th orderdial 9 in register 3 is in direct alignment with the leftmost bank ofkeys 4, and when a divisor digit other than is set up on those keys.Accordingly, the following rules of procedure apply:

1) The given decimal in the divisor is moved mentally, and noted, sothat it precedes the leftmost real digit.

(2) The given decimal in the dividend is moved mentally, and noted,identically. as in the divisor, in direction and the number of orders.

(3) That keybord decimal marker 23 (FIG. 1) is turned to decimalizewhich will set off as many key banks leftward therefrom as there areorders to the left of the moved dividend decimal.

(4) A decimal marker 24 is shifted so that one more order of dials 10 isset off to the left therefrom than the number of key banks to the leftof the above turned marker 23.

(5) The dividend is then setup on the keyboard about the above turnedmarker 23 with the moved decimal thereof coinciding with the turnedmarker 23, and is entered into the machine as previously explained.

(6) The divisor is then setup on the keyboard with the highest orderreal digit thereof on the leftmost key bank.

(7) Then division cycling is initiated, preferably by key 6 whereuponthe quotient is registered in register 2, correctly decimalized by themarker 24 preset as above explained.

The following three problems exemplify the application of the aboverules.

In the above Table No. 1, problem (b), the 0 under the Marker 23 columnindicates that in such instances no key banks are set off leftward of amarker 23. In fact, no marker 23 is turned for decimalizing, in thiscase, since the first real digit of the divisor must be set in theleftmost key bank and, in one preferred form, as illustrated, no decimalmarker 23 is provided left adjacent thereto. In another form, notillustrated, a marker 23 may also be mounted on the keyboardrespectively left adjacent, and another marker 23 may be mounted rightadjacent the leftmost and rightmost bank of factor keys.

When several quotients are to be accumulated, it is preferred that the9th order dial 1%) in register '2 be the highest order dial that mayregister a derived quotient digit so that the 10th order dial stands asan overflow order, only to register carries from the 9th order dial. Inorder to effect this, the dividend is so entered into the computationthat at least the first derived quotient digit will be 0. Accordingly,the following rules apply:

(1a) The decimal in the divisor of each problem is moved mentally andnoted as stated hereinabove for rule 1.

(2a) The decimal in the dividend of each problem is then moved mentallyand noted as stated hereina-bove for.

rule 2.

(3a) Then that marker bar 23 is turned to decim-alize which sets off onemore keybank to the left therefrom than the number of orders to the leftof the moved deci- 1 about the turned marker 23 with the moved decimalof each coinciding therewith, and are entered into the machine aspreviously explained.

(6a) Each divisor is then set up on the keyboard with the highest orderreal digit thereof on the leftmost keybauk 4.

(7a) After entering each dividend and setting up its respective divisor,division cycling is initiated preferably by key 6 whereupon eachquotient is registered and totaled in register 2, correctly decimalizedby the marker 24 which has been preset according to rule 4a.

Decimalizing the totaled quotients of three division problems A, B, andC, in accordance with the above rules is accomplished as follows:

There are 4 orders of digits to the left of the moved decimal in problemC, the largest number of such orders of all the dividends. Accordingly,that decimal marker bar 23 is turned which sets off 5 key banks 4leftward of the marker, and register 2 decimal marker 24 is shifted sothat 6 orders of dials 10 are set off leftward therefrom. The dividendsare entered about the turned marker 23' and the divisors are set up withthe righest order real digit of each in the leftmost keybank. Thequotient of each problem A, B, and C is listed in Table 2 in the columnunder the heading Each. In the column under Totaled are the results asthey would appear in register 2; the first result being the quotient ofproblem A, the second result being the sum of the quotients of problemsA and B, and the third result being the sum of the quotients of thethree problems.

In this embodiment limitation of a quotient to a desired number ofdigits may be accomplished in two ways. The preferred one of thesemethods is by presetting a selected tabulator key 16 and initiatingdivision cycling by key 7. Selection of the tabulator key is simple.That key '16 is depressed which bears the numeral corresponding to thenumber of the dial 10 in register 2 in which the lowest order quotientdigit is to be registered. If, for example the accumulated quotients Cin Table 2 were to be limited to two orders right of the decimal, thelast wanted digit appears in the dial of register 2 under the numeral 3on channel 42. Accordingly, the tabulator key 16 hearing that numeral isdepressed. Then upon cycling of the machine by key 7 for each of theproblems A, B, and C in Table 2, each division process will terminatewhen the true quotient digit is derived and registered in dial 10 underthe numeral 3. Thus the operator can determine to how many significantdigits or decimal places the computation should be carried out, themachine stopping automatically upon reaching the predetermined place.

Another method for limiting a quotient is as follows: Marker 24 islocated to set off as many orders of dials 14) to the right of themarker as the number of digits desired to the right of the decimal. Thenthat keyboard marker 23 is turned which sets olf one more order ofkeybanks to the right therefrom than the number of orders of dials tothe right of marker 24. The dividend and divisor are treated as setforth in rules 1, 2, 5, and 6, and key 6 is used for cycling of themachine.

DECIMALS IN MULTIPLICATION Setting of a decimal marker 25 (FIG. 1) tomark off decimally a product in register 3 is made in accordance withthe well known principle of marking off a product so that the orders tothe right of the decimal therein corresponds to the sum of the orders tothe right of the decimal in the multiplier and in the multiplicand. Theordinal, step-by-step shifting of the carriage during multiplication, aspreviously explained, may be made selectively either leftwardly orrightwardly; correspondingly, the multiplier must be entered into themachine by means of keys as when reading the multiplier from left toright or from right to left. Multiplication may be initiated with thecarriage in any one of its ordinal positions. Nevertheless, whenproducts of a plurality of computations are to be accumulated, it ispreferred to place the carriage in the same starting position for eachcomputation. This may be accomplished by presettin-g that tabulator key16 which bears the same numeral as the numeral on channel 42 above thedial in alignment with the 0 mark 58 on the right of channel 22 when thecarriage stands in its selected start position. Such a dial 10 will bereferred to as the start dial.

(1) In order to indicate the decimal in a multiplier in dials 10,

(a) With the machine in start position and conditioned for leftwardordinal shift of the carriage, a marker 24 is moved so as to set off asmany dials 10 leftward therefrom (the first of such dials being thestart dial) as there are orders to the left of the decimal in themultiplier, but

1 With the machine in start position and conditioned for rightwardordinal shift, a marker 24 is moved so as to set off as many dialsrightward therefrom (the first of such dials being the start dial) asthere are orders to the right of the decimal in the multiplier.

(2) The multiplicand is set-up on keys 4 and that marker bar 23 isturned to viewing position which coincides with the decimal in themultiplicand.

(3) A marker is then moved to set-off as many dials 9 to the right ofthe marker as the sum of the number of dials 10 to the right of marker24 and of the number of keybanks to the right of the turned marker 23.

Another method for setting a marker 25, after setting markers 24 and 23as set forth in rules 1 and 2, is to shift the carriage so that thefirst dial 10 left of marker 24 is in alignment with 0 mark 58, and thento move a marker 25 so as to align with the turned marker 23. Thecarriage is then returned to start position. This method eliminates themental totaling called for in rule 3.

When two or more products are to be accumulated, marker 24 is set as inrule la in accordance with the multiplier having the largest number oforders to the left of the decimal, or as in 1b in accordance with themultiplier having the largest number of orders to the right of thedecimal, depending on whether the multipliers are being entered asreading from left to right or right to left. The multiplicands are setup about a marker bar 23 turned to viewing position, and a decimalmarker 25 for the accumulated products is preset as instructed in rule3.

When working from left to right and multipliers having lesser number oforders to the left of the decimal than in the multiplier having thelargest number of such orders are entered, zeros are entered before theleftmost digit of the lesser ordered multipliers to fill them out or tospread them to have the same number of orders as in the multiplierhaving the largest number of such orders. The purpose of this is to havethe products of each prob- Spreads Multiplicands Multipliers Left shiftand Rightshitt and working L-R working R-L (Marker 23) (Marker 24)(Marker 24) Another set of markers 40 and 41 is provided on channels 22and 44 for marking off the multiplier in dials 10 and the product indials 9 respectively. These markers are stationary, i.e., they do notmove with the carriage, and their setting is as follows:

When working from right to left, a marker 40 is positioned to set off asmany orders of dials 10, up to and including the start dial as there areorders to the right of the decimal in the multiplier. Then marker 41 isshifted leftward from the turned marker 23 as many orders of key banksas the value of the numeral on channel 22 to the right of set marker 40.After completion of the computation the carriage is returned to itsstart position whereupon the markers 40, 41 mark off the respectiveregistrations decimally correct.

When working from left to right, a marker 40 is positioned to the leftof that numeral on channel 22, which numeral has the same value as thenumber of orders to the right of the decimal in the multiplier. Thenmarker 41 is shifted leftward from the turned marker 23 as many ordersof key banks as the value of the numeral to the right of the set marker40' on channel 22. Upon completion of the computation, markers 40 and 41mark off the respective registrations decimally correct.

Accumulated products may also be decimalized by marker 41. Marker 40 isset as explained above in accordance with the multiplier of the grouphaving the largest number of orders to the right of the decimal. Whenthe multipliers are entered right to left, the orders to the right ofthe decimal are filled in or spread to equal the number of orders in themultiplier having the largest number of such orders. When themultipliers are entered left to right, the orders to the left of thedecimal are spread to equal the number of orders in the multiplierhaving the largest number of such orders, and in the last computationthe multiplier orders to the right of the decimal are spread, ifnecessary, to equal the number of orders in the multiplier having thelargest number of such orders.

What I claim is:

1. A decimal point indicating device for the registers of a calculatingmachine comprising: a channel means of uniform thickness material andformed of a pair of substantially outwardly divergent continuously planelongitudinal flanges projecting directly from base web meanstherebetween, said base web means being securable to said machine andeach said flange having an inner and an outer plane face and alongitudinal edge parallel to-the same on the other flange, the edges ofsaid flanges being spread a greater extent than the flanges at said baseweb means, and movable pointer indexing means constructed and arrangedto ride on said edges and to yieldably grip only the outer faces of saidflanges for slidable guided positioning therealong and for indexingappropriate decimal numerical registrations in said register means,whereby said spread edges provide substantial support for said pointerindexing means with minimal frictional contact area between said edgesand said pointer indexing means, While the area contact of said webmeans with said machine is minimized and wherein said pointer indexingmeans straddles said flanges and is formed with depending resilientfingers inclined inwardly against said outer faces of said flanges foryieldably frictionally gripping said outer faces of said flangesintermediate said edges and the intersection of said flange with saidweb means and spaced from said web means for holding said indexing meansat any decimalizing position therealong.

2. A decimal point indicating device for the registers of a calculatingmachine comprising: a channel means of uniform thickness material andformed of a pair of substantially outwardly divergent continuously planelongitudinal flanges projecting directly from base web meanstherebetween, said base Web means being securable to said machine andeach said flange having an inner and an outer plane face and alongitudinal edge parallel to the same on the other flange, the edges ofsaid flanges being spread a greater extent than the flanges at said baseweb means, and movable pointer indexing means constructed and arrangedto ride on said edges and to yieldably grip only the outer faces of saidflanges for slidable guided positioning therealong and for indexingappropriate decimal numerical registrations in said register means,whereby said spread edges provide substantial support for said pointerindexing means with minimal frictional contact area between said edgesand said pointer indexing means, while the area contact of said webmeans with said machine is minimized and wherein said pointer indexingmeans straddles the edges of said flanges and is constructed andarranged with a first skirt and at least one second skirt depending fromopposite sides of said indexing means, said first skirt being resilientfor yieldably gripping on the outer face of one of said flanges and fordrawing said second skirt against the outer face of the other of saidflanges, both said skirts conforming with the spread angulation of theouter faces of said flanges and, under the influence of said resilientfirst skirt and the cooperation of both said skirts, constantly pressingagainst said outer flange faces, and a knob secured on said pointerindexing means for affording manual positioning thereof along saidchannel means.

3. A decimal indexing channel unit adapted for mounting on a computingmachine in decimalizing relation to a register of the machine, saidindexing channel unit comprising channel means formed of a pair ofsubstantially outwardly divergent longitudinal flanges projecting fromWeb means therebetween and terminating in parallel longitudinal outeredges for defining a guide passageway; movable pointer indexing meanscomprising a slide-body having an outwardly visible top face and havingsupport surfaces beveled to conform with the divergent inner surfaces ofsaid flanges for sliding contact engagement therewith and forlongitudinal guidance thereby, said slide-body being formed with supportlimit shoulders extending therefrom between said support surfaces andsaid top face for overlying and sliding on the edges of said flanges andwith a groove transverse the said visible top face of said slide-bodyand its said shoulders, and

spring means constructed and arranged for being inset facilitate endwiseshifting of said indexing means, along a said channel means, saidC-spring means forming a deci2 imalizing index for locating the decimalpoint in a computation on said register 4. A decimal inde-xingchannelunit adapted for mounting on a computing machine in decimalizingrelation to a register of the machine, said indexing channel unitcomprising channel means formed of a web having parallel longitudinalspaced edges, and a pair of substantially outwardly divergentlongitudinal flanges projecting from said edges of said webtherebetween, for defining a guide passageway, said flanges each havingan inner and an outer surface; movable pointer indexing means comprisinga slide body having an outwardly visible top face and support surfacesbeveled to conform with the divergent inner surfaces of said flanges forsliding and supporting engage ment with said flanges and forlongitudinal guidance thereby, said slide-body being formed with agroove transverse the said visible top face of said slide-body, andC-spring means constructed and arranged for being inset said groove withthe center portion of said spring means protruding upwardly from saidtop face of said slide-body, with the extremities of said springresiliently embracing said outer surfaces of said flanges, and with apair of intermediate spring portions, one said portion being betweeneach extremity and said center portion of said spring, said intermediatespring portions engaging said slide-body in said groove for spreadingsaid extremities upon depression of said protruding portion for freeingsaid spring extremities from embracing contact with said flanges,thereby to facilitate endwise shifting of said indexing means along saidchannelmeans, said C-spring means forming a decimalizing index forlocating the decimal point in said register.

5. The combination according to claim 4 wherein said slide body isfurther characterized as having a bottom face interconnecting saidsupport surfaces, and said bottom face being substantially widerlaterally than said web, so that said support surfaces are spaced inrelation to the spacing of the flanges of said channel means as tomaintain said bottom face spaced from said Web in said passageway, outof rubbing contact with said web.

6. A decimal indexing channel unit adapted for mounting on a computingmachine in decimalizing relation to a register of the machine, andcomprising a plane channel web having parallel spaced first and secondside edges, first and second longitudinal channel flanges projectingdirectly from the respective said side edges of said web, said flangesbeing continuously and entirely plane, and being mutually angulariydivergent from the Web, and with their outer edges being mutuallyparallel and co planar, and parallel to said web, so that said outeredges form a pair of'rails, a pointer indexing marker constructed andarranged for riding on both said rails, and comprising a plane markerbody formed so as to be supported upon both said rails and having firstand second longitudinal edges overlying and extending only to the outercorners of said rails, at least one pointer integral with and extendingbeyond a said longitudinal edge of said marker.

body, and being coplanar with said body, first retaining lug meansdepending from said first longitudinal edge of said marker body, andextending inwardly to lie against the outer surface of and conform tothe angularity of said first longitudinal flange, and second lug meansdepending from said second longitudinal edge of said marker body andcomprising a pair of resilient lug fingers extending longitudinally'fromsaid second lug means in opposite directions and resiliently bearingagainst the outer surface of said second longitudinal flange, fordrawing said first retaining lug means against said first longitudinalflange and causing said pointer indexing marker and its first and secondlug means to resiliently grippingly engage said channel flanges forvariable positioning along said flanges,

7. A decimal indexing channel unit adapted for mounting on a computingmachine in decimalizing relation to a register of the machine, saidindexing channel unit comprising channel means formed of a web havingparallel longitudinal spaced edges, and a pair of substantiallyoutwardly divergent continuously plane longitudinal flanges projectingdirectly from said edges of said web therebe tween, for defining a guidepassageway, said flanges each having an inner and an outer plane surfaceand an edge surface displaced from said web; movable pointer indexingmeans constructed and arranged for riding on the edge surfaces of saidflanges and comprising a slide body formed of sheet material having twomarginal edges, two spaced extensions on a first said marginal edgeformed downwardly to conform to and grip the outer plane surface of oneof said flanges for alignment and guidance thereby, and a resilientextension on the second said marginal edge formed downwardly to conformto and yieldably grip the opposing outer plane surface of the second ofsaid flanges for yieldably holding said indexing means in decimalizingposition along said channel means.

8. A decimal indexing channel unit adapted for mounting on a computingmachine in decimalizing relation to a register of the machine, saidindexing channel unit comprising channel means formed of a web havingparallel longitudinal spaced edges, and a pair of substantiallyoutwardly divergent continuously plane longitudinal flanges projectingdirectly from said edges of said web therebetween, for defining a guidepassageway, said flanges each having an inner and an outer plane surfaceand an outer edge displaced from said web; movable pointer indexingmeans constructed and arranged for riding on the edges of said flangesand comprising a slide body having two marginal edges, two spacedextensions on a first said marginal edge formed downwardly to conform toand grip the outer plane surface of one of said flanges for alignmentand guidance thereby and a resilient extension formed on the second saidmarginal edge formed downwardly to conform to and yield-ably grip theopposing outer plane surface of the second of said flanges for yieldablyholding said indexing means in dccimalizing position along said channelmeans.

9. The combination according to claim 8 wherein ordinally spaced indiciaare carried on said web situated in ordinal alignment with and forcorresponding perm'anently to the orders of said register on the visibleface of said web between said flanges, and so that said flanges havetheir upper edges above said web so as to protect said indicia fromengaging contact with an obliteration by said indexing means.

10. The combination according to claim 8 wherein said web comprises avisible face between said flanges, and wherein indicia are carried onsaid web corresponding positionally to the orders of said register onsaid visible face between said flanges, and so that said flanges spacesaid movable indexing means from "and protect said indicia from rubbingcontact of said indexing means.

11. A decimal indexing channel unit adapted for mounting on a computingmachine in decimalizing relation to a register of the machine, saidindexing channel unit comprising channel means formed of a web havingparallel longitudinal spaced edges, and a pair of outwardly divergentcontinuously plane longitudinal flanges projecting directly from saidedges of said web therebetween, for defining a guide passageway, saidflanges each having an inner and an outer plane surface and an edgesurface displaced from said web; and movable pointer indexing meansconstructed and arranged for riding on the edge surfaces of said flangesand comprising a slide body having two marginal edges, two spacedextensions located at the extremities on a first said marginal edge andformed downwardly to conform to and grip the outer plane surface of oneof said flanges for alignment and guidance thereby, and an extensionlocated generally centrally on the second said marginal edge and formeddownwardly and comprising a pair of laterally extending resilientfingers formed to grip the outer plane surface of the second of saidflanges for yieldably holding said indexing means in a decimalizingposition along said channel means.

References Cited in the file of this patent UNITED STATES PATENTS791,903 Hawkins June 6, 1905 1,580,858 Schluns Apr. 13, 1926 2,148,806Da Voll Mar. 30, 1936 2,299,284 Steidemann Oct. 20, 1942 2,329,180 BoydSept. 14, 1943 2,341,681 Andersen Feb. 15, 1944 2,456,676 Chowns Dec.21, 1948 2,795,205 Wells June 11, 1957 FOREIGN PATENTS 401,412 GermanySept. 4, 1924 371,996 Italy June 12, 1939 187,995 Switzerland Apr. 16,1937

1. A DECIMAL POINT INDICATING DEVICE FOR THE REGISTERS OF A CALCULATINGMACHINE COMPRISING: A CHANNEL MEANS OF UNIFORM THICKNESS MATERIAL ANDFORMED OF A PAIR OF SUBSTANTIALLY OUTWARDLY DIVERGENT CONTINUOUSLY PLANELONGITUDINAL FLANGES PROJECTING DIRECTLY FROM BASE WEB MEANSTHEREBETWEEN, SAID BASE WEB MEANS BEING SECURABLE TO SAID MACHINE ANDEACH SAID FLANGE HAVING AN INNER AND AN OUTER PLANE FACE AND ALONGITUDINAL EDGE PARALLEL TO THE SAME ON THE OTHER FLANGE, THE EDGES OFSAID FLANGES BEING SPREAD A GREATER EXTENT THAN THE FLANGES AT SAID BASEWEB MEANS, AND MOVABLE POINTER INDEXING MEANS CONSTRUCTED AND ARRANGEDTO RIDE ON SAID EDGES AND TO YIELDABLY GRIP ONLY THE OUTER FACES OF SAIDFLANGES FOR SLIDABLE GUIDED POSITIONING THEREALONG AND FOR INDEXINGAPPROPRIATE DECIMAL NUMERICAL REGISTRATIONS IN SAID REGISTER MEANS,WHEREBY SAID SPREAD EDGES PROVIDE SUBSTANTIAL SUPPORT FOR SAID POINTERINDEXING MEANS WITH MINIMAL FRICTIONAL CONTACT AREA BETWEEN SAID EDGESAND SAID POINTER INDEXING MEANS, WHILE THE AREA CONTACT OF SAID WEBMEANS WITH SAID MACHINE IS MINIMIZED AND WHEREIN SAID POINTER INDEXINGMEANS STRADDLES SAID FLANGES AND IS FORMED WITH DEPENDING RESILIENTFINGERS INCLINED INWARDLY AGAINST SAID OUTER FACES OF SAID FLANGES FORYIELDABLY FRICTIONALLY GRIPPING SAID OUTER FACES OF SAID FLANGESINTERMEDIATE SAID EDGES AND THE INTERSECTION OF SAID FLANGE WITH SAIDWEB MEANS AND SPACED FROM SAID WEB MEANS FOR HOLDING SAID INDEXING MEANSAT ANY DECIMALIZING POSITION THEREALONG.